AB0819 Impact of childbirth on the sacroiliac joints in non-radiographic axial Spondyloarthritis
Authors: M. Yasmine, D. Ben Nessib, H. Ferjani, W. Triki, K. Maatallah, D. Kaffel, W. Hamdi
Journal: Annals of the Rheumatic Diseases (2022)

Background The era of magnetic resonance imaging (MRI) has contributed to a better assessment of patients with early disease stages of axial spondyloarhtis (ax-SpA), to the extent that a new entity has emerged. Indeed, the spectrum of SpA has broaden to include non-radiographic axial spondyloarthritis (nr-axSpA). Childbirth has been found to be associated with bone marrow edema (BME) in the sacroiliac joints (SIJ) [1], yet the extent of these lesions is inadequately described, which complicates the distinction with nr-axSpA. Objectives This study aimed to explore the impact of childbirth on MRI findings and BME in nr-axSpA. Methods We conducted a cross-sectional study including women diagnosed with nr-axSpA according to the ASAS (Assessment of SpondyloArthritis international Society) criteria. Socio-demographic data as well as childbirth history were recorded. The sacroiliac joints manoeuvers’ examination were also transcribed. Ultrasound of the SIJ as well MRI-SIJ was performed in all the women. The sequence protocol included the following: T1-weighted, T2-weighted and axial STIR and were scored for BMO. We investigated an association between the number of children and MRI abnormalities mainly the presence of BME. The level of significance was fixed for p&lt;0.05. Results The study included 30 women. The mean age at diagnosis was 40±9.8 years old [21-59] and the mean age at inclusion was 49±11 years old [26-74]. The median number of children was 2 [0-7]. Half of the patients were multiparous. Doppler ultrasound of the SIJ was found in 59.1% of cases. Overall, 36.7% of the women fulfilled the ASAS definition of a positive MRI. BME was displayed on STIR MRI sequence in 26.5% of cases and was equally present at the right SIJ compared with the left (26.7% vs 23.3%). Gadolinium enhancement was found in 16.7% of cases and subchondral erosions were found in 36.7% of cases. There was no association between the different sacroiliac maneuvers on physical examination and the number of children: distraction test (p=0. 145), compression test (p=0.088), Gaenslen test (p=0.475), and Mennel test (p=0.088). BME was more frequent among multiparous women (33% vs 29%) without reaching a statistically significant difference (p=0.635). There was no association between the number of children and Hyper T1 (p=0.608), T1 gadolinium (p=0.55) as well as sclerosis (p=0.55). Similarly, there was no association between the presence of Doppler signal on ultrasound and multiparity (p=0.5). Conclusion Our study showed that MRI-SIJ findings were similar in nr-axSpA women regardless of the number of children, mainly BME. More trials are needed to evaluate the discriminatory capacity of MRI abnormalities and to palliate to the lack of specificities of the ASAS MRI criteria. References [1]Germann C, Kroismayr D, Brunner F, Pfirrmann CWA, Sutter R, Zubler V. Influence of pregnancy/childbirth on long-term bone marrow edema and subchondral sclerosis of sacroiliac joints. Skeletal Radiol . 2021;50(8):1617-1628. Disclosure of Interests None declared